Thermal Spray KPIs: Benchmarks for Deposit Efficiency, Yield, Booth Utilization and Cost of Quality

Use a benchmark as a reference point for spotting a gap worth investigating, not as a target. Your own trend for each process, measured over several batches rather than a single run, says more about your coating cell than any published range.

Every figure shows its basis. A superscript number links to a public source in the Sources list, and the sentence gives that source's context. A figure marked no cited source is kept exactly as originally published because no public source stating it has been verified, so treat it as illustrative.

At a glance

Deposit efficiency

Deposit efficiency is the headline KPI because it converts directly into feedstock spend, and it varies sharply by process. Typical benchmark bands run 40 to 60 percent for plasma of oxides, 50 to 70 percent for HVOF carbides, 65 to 85 percent for twin-wire arc metals, and above 90 percent for cold spray of ductile alloys no cited source.

World-class shops hold the top of their process band consistently, run to run. Deposit efficiency is not spray rate: Oerlikon Metco lists an approximate HVOF application rate of 40 to 200 g/min (5 to 26 lb/h)¹, and deposit efficiency decides how much of that feedstock ends up on the part.

For example, feedstock per unit of coating scales with 1 / deposit efficiency, so a gain of ten points cuts it by 10 / (DE + 10): 20 percent from a 40 percent base and 17 percent from a 50 percent base. Ten points of efficiency gain therefore cuts feedstock cost by 15 to 22 percent on the same coating when the starting efficiency is roughly 35 to 57 percent.

How to measure

• Weigh feedstock consumed against deposited coating mass on a coupon.
• Track it on a tier board, by process and by coating.

What moves it

• Parameter stability from run to run, so the cell holds the top of its band.
• Process choice matched to the coating, since the bands differ sharply by process.

Measure deposit efficiency from coating weight deposited and material sprayed. Deposition Rate

First-pass yield

First-pass yield tracks quality and capacity together, since every reject consumes booth time that produced nothing sellable. Mature production coating lines target first-pass yields of 95 percent or better, meaning reject rates at or below 5 percent no cited source.

World-class precision aerospace and medical coating cells push toward 98 to 99 percent on stable geometries no cited source. Anything under 90 percent signals systemic prep, parameter or masking problems rather than random variation no cited source.

How to measure

• Divide parts passing inspection on the first attempt by parts coated.
• Trend it batch over batch.
• Pair the rate with a defect Pareto so the dominant failure mode is visible.

What moves it

• Attacking the dominant failure mode, whether adhesion, thickness or masking bleed.
• Prep control.
• Parameter control.

Trend your reject rate batch over batch with the Overspray Loss calculator, which measures the share of coated parts that fail inspection.

Booth utilization

Booth utilization tells you whether your most expensive asset is actually spraying. Typical job shops run 45 to 60 percent booth utilization once prep, changeover, cooldown and inspection idle time are counted, while well-scheduled cells reach 65 to 75 percent no cited source.

Chasing much above 80 percent usually trades throughput for missed maintenance and quality slips no cited source. The biggest lever is rarely the gun.

How to measure

• Divide gun-on hours by available booth hours.
• Log the idle time by cause: prep, changeover, cooldown or inspection.

What moves it

• Decoupling grit-blast prep and masking from the booth.
• Parts that arrive kitted and ready, so the torch stays on instead of waiting on upstream steps.

Estimate the gun-on and handling time a workload needs with the Spray Time Per Part calculator.

Non-productive time in the spray cycle

Non-productive time inside the spray cycle is a KPI in its own right, separate from booth-level utilization. Automated robot cells with clean part flow run 8 to 12 percent non-productive time for indexing, cooling and pattern checks, while manual spraying with frequent re-clamping and cooldown often runs 20 percent or more no cited source.

World-class cells hold under 10 percent no cited source by overlapping part load and unload with cooldown and by fixturing to eliminate re-clamps.

How to measure

• Separate the non-productive allowance from gun-on time in each cycle.
• Compare datasheet cycle time with actual cycle time to see whether the gap is deposition speed or handling overhead.

What moves it

• Overlapping part load and unload with cooldown.
• Fixturing that eliminates re-clamps.

Convert a coating workload into gun-on and handling time per part. Spray Time Per Part

Cost of quality

Cost of quality, driven by rework and scrap, is where yield turns into money and where small percentage moves matter most. Best-in-class coating shops hold cost of quality under 3 to 5 percent of total coating cost, while struggling cells run 10 percent or higher once you count strip-and-recoat labor and scrapped feedstock no cited source.

A rejected part carries the full sunk cost of powder, masking, booth time and grinding. Depending on price and margin per part, a single reject can equal two to three good parts of margin.

How to measure

• Add strip-and-recoat labor, scrapped feedstock, masking and booth time for every reject.
• Divide by total coating cost for the period.

What moves it

• An improvement target tied to the dominant defect, not to the aggregate reject rate.
• The first-pass yield levers above, since every reject feeds this number.

Start from the reject rate itself with the Overspray Loss calculator.

Grind allowance and finishing yield

Grind allowance and finishing yield are quieter KPIs that reveal feedstock and labor waste. Thermal spray builds engineering coatings typically 0.1 to 10 mm thick², and every layer you grind off was bought and sprayed first.

World-class cells hold grind allowance to the minimum that reliably corrects roundness and surface finish, often 0.05 to 0.08 mm radial on ground carbide, rather than a blanket 0.10 mm that wastes 20 to 30 percent extra coating no cited source.

Every 0.02 mm of unnecessary allowance is feedstock you buy and then grind off, so tightening it improves both material yield and finish cell throughput at once.

How to measure

• Divide finished thickness by as-sprayed thickness.
• Record the allowance specified for each part number.

What moves it

• Allowances set per part from measured roundness and finish needs, not a blanket figure.
• Spray thickness control that keeps the as-sprayed build close to plan.

See how much feedstock a thicker build consumes with the Powder Consumption calculator or, for wire processes, the Wire Consumption calculator.

Masking labor per part

Prep and masking hours per part expose whether labor, not spraying, is your real constraint. On feature-heavy precision work, masking can consume 15 to 40 percent of cell labor no cited source.

Moving high-volume parts from hand-applied tape and dots to reusable machined or silicone masking fixtures raises one-time setup but drives per-part masking labor down sharply at volume. Know the quantity at which a fixture pays back before you buy it.

How to measure

• Record masking minutes per part.
• Compare them against a standard for each part number, so drift shows before it hits margin.

What moves it

• Reusable machined or silicone masking fixtures for high-volume parts.
• Hand masking kept for low-volume work, where a fixture would not pay back.

Find the crossover quantity at which a masking fixture pays back. Masking Labor Cost

How to build your own baseline

Improve these KPIs in the order they cascade. Stabilize deposit efficiency first, because it moves both material cost and yield, then lift first-pass yield through prep and parameter control.

• Write each KPI's definition down and keep it fixed.
• Set each target against the band for your process, not a generic number.
• Review trends over multiple batches rather than reacting to a single run.
• After yield, attack booth utilization by decoupling prep from spraying, then tighten grind allowance and masking labor.

A coating cell that holds top-of-band deposit efficiency, 95-plus percent yield, 70 percent booth utilization and sub-5 percent cost of quality is operating at the benchmark frontier for the industry no cited source.

Safety is one KPI with a public industry average. In 2024, U.S. metal coating, engraving and allied service shops (NAICS 332812) recorded 4.1 total recordable injury and illness cases per 100 full-time workers, with 3.1 days-away, restricted or transferred (DART) cases, against 2.7 and 1.7 for all U.S. manufacturing³. That industry code covers metal coating services in general, not thermal spray shops alone.